This British Geological Survey (BGS) marine sampling survey took place in July 2004 in the area of Fladen, North Sea on board Vidar Viking. The objective was to drill a trial borehole (04/1, +58+00/535) in the North Sea to allow testing of the drilling rig and coring tools, particularly the piston corer. The site chosen met the specified requirements of test, i.e. a soft to firm downhole transition. The site is located in the Witch Ground Basin close to previously drilled BGS boreholes (75/33 and 77/2).